General Category => Engine & Transmission => Topic started by: kartjockey on September 05, 2018, 05:38:07 PM
-
1936 to 38 crank 2-1/4" stroke. Even though this crank has the least amount of counter weight. Due to the crank pin being closer to center of crank with a lighter weight aftermarket rod and piston these engines were close to being ideally balanced. Note! there are no markings on this crank forger is unknown. Simplex did do the machining.
-
Note! even more weight was added to counterbalance rim is machined different than previous crank. This crank is most desired to use in 39 - 49 engines as it brings engine close to balance.
-
This is crank for 52-56 M models with Wico mag it has same counterbalance weight as "L" and "LM". It is the most widely known "M" crank.
-
This is most desirable "M" stock Simplex crank as it has the most counterbalance weight Simplex used. It is still not enough to balance out a 125 cc ideally and way short of weight for a 150 cc. This crank began being used when Phelon mags came out. Simplex had to increase weight because Phelon flywheels are much lighter than Wico flywheels. These cranks have wider and larger diameter counterbalance than previous cranks.
-
Great info! I had no idea there was a late M crank. The Sportsman that I built had a crank with the bigger weight, and additional counterweight was added by Gary Wollard. That was the smoothest running engine I have ever had.
-
Excellent , Tom . Thank You , again .
Pete . :)
-
Anyone ever do a comparison of Wayne's crankshaft to original ones? I have been running one of his for around ten years but I have never seen another running bike to compare it to. Mine is 53 M/Wico mag.
Carl
-
Anyone ever do a comparison of Wayne's crankshaft to original ones? I have been running one of his for around ten years but I have never seen another running bike to compare it to. Mine is 53 M/Wico mag.
Carl
Are you running his one piece billet crank or the one with a replacement shaft with the original counterweight?
-
My crank from Wayne is a one piece crank to the best of my memory. It's been 9 or 10 years since I installed it. Just wondering if I can do better with an original. Didn't know that Wayne sold more than one style of crankshaft. Are there any performance differences between the different shafts.
Thanks,
Carl
-
I have never had one of Wayne’s billet crankshafts, but the one I saw was really nicely made. Wayne told me they were too expensive to make and therefore changed his method. What he does now is remove the old shaft from the counterweight, make a new shaft, and then has them tig welded together. I have used 2 of this style with excellent results. I have another going in a motor for my truck.
-
As you have had good performance with his crankshafts, I guess that I should leave well enough alone and not worry about looking for something better. Thank your time on my questions.
Sincerely,
Carl
-
One of Wayne's rebuilt crankshafts. This looks like a late M counterweight to me.
-
Rick ,
The counter weight , probably . But , the transfer hole seems much bigger than stock .
Pete . :)
-
Rick ,
The counter weight , probably . But , the transfer hole seems much bigger than stock .
Pete . :)
It is only slightly larger, just looks like that because of the weld circle I believe.
-
I'm looking at the rod 'pin' for reference .
Side by side , the welded crank seems to have more than a slightly bigger hole :
(http://www.simplexservi-cycle.com/index.php?action=dlattach;topic=1745.0;attach=11753;image)
(http://www.simplexservi-cycle.com/index.php?action=dlattach;topic=1745.0;attach=11757;image)
Maybe it just me ?
Pete . :)
-
I don't have a stock crank laying around, but I measured Wayne's at .651". Anybody have a stock one they can measure for reference?
-
My 1955 is .648 and I have smoothed it up just a little.
-
My 1955 is .648 and I have smoothed it up just a little.
Thanks! Pete, I guess it's just you! lol
-
My 1955 is .648 and I have smoothed it up just a little.
Thanks! Pete, I guess it's just you! lol
Hmm , wouldn't be the first time . :o ;)
Pete . :)
-
Hey guys, We were looking at a couple of cranks. The one Wayne rebuilt with a new shaft does have a slightly larger hole. Looks like this is because of the cutter used to hollow out the valve and end of the crank. Question, Will the larger hole create more suction or less? If it creates more it should run a bit better on fuel transfer. Anyone have an idea which runs better or if there is any difference at all. Bob
-
Hey guys, We were looking at a couple of cranks. The one Wayne rebuilt with a new shaft does have a slightly larger hole. Looks like this is because of the cutter used to hollow out the valve and end of the crank. Question, Will the larger hole create more suction or less? If it creates more it should run a bit better on fuel transfer. Anyone have an idea which runs better or if there is any difference at all. Bob
Bob ,
The intake path should at least match the venturi size for the carb for optimum intake performance .
Manufacturers have gone by the flow velocity . Smaller carbs with higher velocities are better for engines used mostly at mid range RPM. Engines that are mostly used at high RPM were given larger carbs for lower flow velocities.
Not sure just how Simplex calculated the intake , but , according to 'general' practices , smaller would seem better for our relatively low RPM motors . And , the longer intake path ( from carb mount to crankcase ) should also aid low end performance . RPM gain is a bit slower ( pretty sure that's how it is ) .
Of course , if you're building a race version , LOL , all that^ needs revision .
Pete . :)